Warrant: Wife, son of Thomas Matusiewicz also suspects in Del. courthouse shooting

Sixty-eight-year-old Thomas Matusiewicz allegedly opened fire in the lobby of the New Castle County Courthouse Monday morning before of a hearing that was part of a long and bitter legal battle between his son David and David's ex-wife, Christine Belford. Police said Matusiewicz then took his own life.

Now, according to a search warrant affidavit filed by Texas authorities, Matusiewicz's wife Leonore and son David are also suspects in the shooting, whose victims included both Belford and her friend Laura Mulvey. Both were fatally shot at close range as they entered the building for the custody hearing regarding the three children Belford shared with David Matusiewicz.

The affidavit to search Thomas Matusiewicz's Edcouch, Texas home states that Thomas, Leonore and David Matusiewicz are all suspected of "intentionally and knowingly participating in a murder," though police said it was Thomas who actually pulled the trigger. Leonore and David are suspected of helping to plot the slayings, according to the document.

The affidavit further asserts that handwritten death certificates for Belford and her attorney were found on Thomas Matusiewicz's body after the gun battle, which also injured two police officers.

Police recovered eight guns from Matusiewicz's property and found five more firearms inside a storage unit. They also seized ammunition, various paper documents and a book eerily titled "Kill All the Lawyers."

Thomas' son David Matusiewicz was in 2009 sentenced to four years in prison and five years of probation after being convicted of international parental kidnapping for fleeing to Central America with his mother and the three young children he shared with Belford, sparking an international search that lasted for a year and a half.

He was also convicted of bank fraud for falsifying documents to obtain a home loan, then transferring the money to a New Zealand bank account. Matusiewicz was released from custody this past September.

Neither David nor Leonore Matusiewicz have been arrested or charged in connection with Monday morning's shooting, though David is currently being detained by federal authorities for allegedly violating the terms of his probation by lying to his probation officer about where he spent the night before the shooting and failing to pay restitution and child support, according to court documents.

He is due in court tomorrow for a hearing addressing those allegations.